It is well known that a polyketone can be synthesized by the polymerization of carbon monoxide and at least one olefin. A variety of catalyst formulations have been described for such a polymerization procedure.
One representative type of catalyst system, which is described in U.S. Pat No. 4,818,810, is formed by the admixture of a Group VIII metal, such as palladium, cobalt or nickel, an anion of an acid having a very low pK.sub.a, e.g. lower than about two, and a bidentate ligand which comprises phosphorus, arsenic or antimony
A more recent patent publication which shows the use of tetrakisphosphine ligands is European Patent Publication No. 408,155 which describes catalyst compositions comprising a Group VIII metal and a tetrakisphosphine of the general formula (R.sup.1 R.sup.2 P).sub.4 R.sup.5 where R.sup.1 and R.sup.2 are hydrocarbyl groups and R.sup.5 represents a tetravalent organic group which connects the four phosphorus atoms and which has a structure of at least two carbon atoms between every phosphorus atom. The catalyst systems described in this patent publication are also said to advantageously include an anion of an acid having a pK.sub.a of less than about four.